Previous single cylinder two-cycle engines have a structure in which the shaft center of a cylinder is offset onto the exhaust side thereof with respect to the rotational center of a crankshaft (for example, Patent Document 1 and 2).
In such a two-cycle engine, because the rotational center of the crankshaft is located at an offset position extending from a connecting rod (hereinafter, referred to as a “con.rod”) in a position such that the con.rod becomes parallel to the shaft center of the cylinder, the height from the rotational center of the crankshaft to the location of the top dead center of a piston may be slightly minimized, contributing to downsizing. Furthermore, the shaft center of the cylinder is offset onto the exhaust side, lowering the side pressure of the sliding surface of the cylinder and the piston on the exhaust side, and preventing seizures or abnormal wear by favorably maintaining the lubrication on the exhaust side where the temperature becomes high.